The development of electron microscopy has made real time or in situ observation of physical phenomena under microscopic scale possible. With transmission electron microscopes (TEM), such phenomenon may be examined on an atomic level. Experimental setup has been developed to allow variables, such as gas environment, temperature, electrical biasing, and mechanical force, to be introduced and controlled in real time. Most in situ specimen holders are built with singular functionality. However, the demand to push to incorporate multiple functions into a single holder has grown recently, for that most events are affected by multiple variables. It is also worth noticing that most of the conventionally available holders only have single-tilt capability, meaning that the ability to achieve high resolution imaging on these holders are limited.
For in situ experiments involving electrical measurements in the TEM, electrodes are typically deposited on the samples and are further wired to the electrical feeds before placing the specimen holder into the TEM. This enables capacity type of electrical field input and is suitable for experiments that needs uniform electrical field. The electrodes are deposited using a focused ion beam (FIB) or by sputtering the electrodes onto the surface of the specimen. Thus, the electrodes cover a larger area on the sample surface making it more difficult for localized biasing and electrical measurements. In addition, for performing biasing/measurement experiments, a probe may be manipulated to make contact with a specific point on the sample. As the manipulation system takes a significant amount of the space, the TEM holders typically have singular functionality and cannot ensure both high sensitivity and high stability.
In some examples, chip-based microelectromechanical systems (MEMS) may be used in the TEM holders. These designs miniaturize the electrical components and integrate them on to a single-use silicon-based chip that has an electron transparent SiN window for observation. However, such systems are limited by the type of the samples that can be used. It may be difficult to mount a thin film sample. Additionally, the ability for dynamic methods such as manipulation of probes and illumination may be limited. As a result, these MEMS holders may not suitable for thin film characterizations.
Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art. Additional advantages and aspects of the present invention are apparent in the following detailed description and claims.